Improvement in low-watee ikdioatoe



@time iuteaatnt THEoDoE e. EI'SWALD AND JAMES BARBoUR, or rRovIDENcE,RHODE ISLAND, `ASSIGNORS TO T. G. EISWALD.

Letters Patent No. 81,483, dated August 25,1868.

'IMPROVEMENT IN LOW-WATER INDICATOR.

TO ALL WHOMIT MAY CONCRN:

Be it known that we, THEODOR Gr. EISWALD and JAMES BARBoUR,-of the cityand county of Providence, and State of Rhode Island, have invented a newand improved Low-Water Indicator; and we do hereby declare that thefollowing is a full, clear, and exact description of tbe constructionand operation of the sanne, reference being had to the accompanyingdrawings, making -a part of this specification, in whichv Figure 1 isalongitudinal vertical section.

Figure 2, a horizontal section through line tra ot' iig. 1. v l

The object of thisinvention is so to construct a. lowwater indicatorthat the fusible plug, when melted, shall not be blown inte the whistle,but shall be forced in another direction, so as to prevent thepossibility of its obstructing or interfering with' the operation ofthe'alarm-apparatus. i

` In the drawings, A represents an expanded andchambered tube, Whichiisattached to the boiler, or to any suitable steamppe, by the connectioner. A

B is a tube screwing into the upper end of the chamber A,"a nd Ganother, screwing into the u`pper`end of tube B, and supporting thewhistle D, the whole forming an instrument whose general outlines arerepresented in iig- 1.5.

' The lower end of -tubeB projects down into the chamberedor expandedportion lof tube A, and there supports a hollow cup, which is suspendedfrom it by ascrew-threa'd connection. A fusible-plug valve,rP, separatesthe interior of cup E from the interor'oftnbe B, seating downward, asseen in g. 1. The steam from the boiler enters chamber A, and thencepasses into the-interior of tube B through an aperture, in the side ofthe tube. It'cannot thence pass upward tothe whistle, since the upperend of tube B is made solid, and there is' no communicationin thatdirection between its cavity and the tube vC above it. When the steamVis superheated, however, from, any canse, it melts and blows outthe'plug P, forcing the latter down into the cup E. 4 The steamthen-.passes into the cup, and from that escapes through pipes e\e,inthe solid walls of the tube B, and through the upper part of cupNI?`to the cavity of tube C, and thence to the whistle, where vit soundsthe'ala'rm. p 'l `i A The whole instrument is exceedingly simple" inconstruction and eiicient in practical operation, blowing all thematerial of' the plug to the bottom of cup E, and preserving the whistlein'good working condition at all times, so'that when the plug isblown-out, the whistle never failsI to sound instantly. m

. Having thus described our invention, whatwe claim as new, end desireto secure by Letters Patent, is'- l. The arrangement of the cup E,fusible plug P, tube or stem B, and openings or side pieces ce, or theirequivalents, when constructed'to operato in the manner described.

2. The arrangement of the above-described apparatus within the hollowglobe,rcylinder, or expanded pipe A, substantially as shown anddescribed. i THEODOR G. EISWALD. [1.. s] JNMES BARBOUR. [L. s.]Witnesses G. W, BLISS,

' EDWIN T. CASE,

CHAs. A..PETTIT,'

SoLoN C. KEMoN.

